Ask a Climatologist

Tuesday, April 22, 2014

Earth, as seen from Apollo 17 on Dec. 7, 1972. (NASA/NASA)

Katharine Mach, co-director of science for the IPCC Working Group II based out of the Carnegie Institution for Science's Department of Global Ecology at Stanford University, is a scientist who worked on the latest IPCC report. She answers your questions about the earth and humans' vulnerability to climate change, what's already happened, will happen in the future and how we might fix this mess. Plus, anything else you've ever wanted to ask a climate scientist.

A Few Things We Learned from Dr. Mach

  • Climate change really is our fault:

“What we know is that the current change that we may see through the century with continued high emissions of greenhouse gases is really unprecedented in terms of the rate. You know, things that happened over millennia in the past, we might see over a century.”

  • A Geo-Engineered Solution?:

“Within the century, some of those techniques may become more common, especially bio energy paired with carbon capture and storage. Some of the other techniques really involve the manipulation of the amount of sunlight that’s entering into the atmosphere, sunlight deflection. And those in some cases will definitely – perhaps rather cheaply, reduce the amount of warming that the planet sees, but they come with trade-offs. So they affect the water cycle of the planet. They don’t reduce the amount of acidification that’s happening in our oceans. And kind of importantly, if you stopped that technique at any one point – if you stopped shooting particles into the stratosphere, warming could go up really rapidly, with potentially severe risks.” 

  • A Cost-Benefit Analysis:

“The report showed if we head toward some of the most ambitious mitigation scenarios, scenarios that would give us a very good chance of staying under a 2 degree C increase above pre-industrial levels – so that’s 3 and a half degrees Fahrenheit, we could get there – the models show – with only a shave off of annual economic growth of .06 percentage points. So that’s almost a rounding error. So a way of thinking of that is we could get to the total level of wealth in 2052 that we would [have gotten to] in 2050.”


Katharine Mach

Comments [38]

John R from NYC

Please invite her back - patience and presentation like hers, more often seen in scientific essays and oxford-style debate aren't familiar to most of BL listeners - but Brian and Katharine should combine for further dissemination in the future. Thank you.

Apr. 28 2014 12:59 PM

A better article on effects of CO2 on plant growth and that of plant growth on climate:

Apr. 24 2014 03:40 PM
Peg from Finger Lakes

To: Alex W and superf88 - the Finger Lakes region is a great place. Plenty of wonderful intelligent people, plenty of water, plenty of affordable properties and Great wineries. Yes we are on top of the Marcellus shale - but the frackers have learned how to determine the gas "sweet spots" and that's where they go to harvest. Those geological sweet spots in NY are near to the PA border and not further north. Although many have taken out leases, those from the non "sweet spot" regions will most likely be ignored for the easy pickings in so many places in the rest of the US and world. Gas companies are starting to not renew leases with many property owners who don't live above the "gravy."

Apr. 23 2014 12:41 PM
Peg from Finger Lakes

Plenty of mosquitoes, black flies and ticks emerging around here - as soon as the ground thawed! There were hardly any of these blood thirsty pests last year. Not that many birds yet (please come and eat up all these nasty bugs!)

Apr. 23 2014 11:38 AM
shaneeza aziz from brooklyn

wow! she was absolute the worst person to talk about climate change! i just started my first year of geology and i could answer these questions way better than she did for this segment.

Apr. 23 2014 10:39 AM
Shane E

Thanks for the informative segment. It is important to understand all of the impacts we are already experiencing due to climate change.

Apr. 23 2014 01:07 AM

Alex W -- we did exactly that! 60 perfect acres -- except that it's right on top of Marcellus Shale! (Imagine the worst.)

Apr. 22 2014 06:57 PM

Isn't the root of all our environmental problems our consumer-driven culture? A little wisdom from the Buddha (which is actually a lot of wisdom) is that our desires are at the root of our unhappiness, and our consumer culture just teaches that we should want more and more.

Vicious cycle, yes?

Apr. 22 2014 11:52 AM
Jessica from Astoria

The impact of air travel is devastating, and is the primarily used by the business, political and industry elite to "make the world go round." John Kerry and Theresa Heinz have private jets to take them around the globe to important meetings on climate change. They, like so many of us, see their carbon footprint as a necessary exception. We will look back at our plane culture the way we now look back on mental models that condoned slavery. I include myself in this problem, but do know people who have sworn off plane travel, and accepted slower transportation models as an urgent requirement to extend our time on earth. I'm not sure we as humans will absorb the profound sacrifices and paradigm shifts required before it is too late.

Apr. 22 2014 11:43 AM

This guest sounded like she was reading from a text, and as cited above she does sound stunted, spouting granular yet oddly anodyne responses while not answering the questions. Now I understand how the IPCC generated the stupendous takeaway that to reduce air-conditioning we should allow more casual-wear in the office. Talk about re-arranging the deck chairs on the Titanic!

Apr. 22 2014 11:43 AM
Greg from NYC

There are horrific reports of mite infestations of humans in the US which seems to be spreaing. Unfortunately, these reports still remain bellow the media radar. A friend of mine is suffering from such an infestation for over a year. I wonder if this is related to the climate change.

Apr. 22 2014 11:39 AM
Fran from Westchester Co.

Why is Brian Lehrer allowing the climatologist to duck every single question which is phoned in? She simply reiterates her spiel about trends but not once while I was listening did she deal with the reasons trends are moving this way or that. One listener asked how could it be that global warming is impacting extremes of both cold and warm. The response did not even start to give us any information about what science sees as the reason this seems to be happening.

Apr. 22 2014 11:37 AM

Could the climatologist please comment on the recent NASA study that suggests slower warming?

Apr. 22 2014 11:37 AM
fuva from harlemworld

jgarbuz: Oh, I'd loooove a segment really analyzing the "so" verbal tic. I think it at least partly reflects the narcissism of millennials. Others think it's an attempt to be causal, down to earth...

Apr. 22 2014 11:25 AM

Can you give us an idea of what it looks like when we reach a point where we know from then on, the situation is basically hopeless? How dramatic is that point? Does it involve mass starvation? How high would extinction rates be? A few species per year?

Apr. 22 2014 11:24 AM
Amy from Manhattan

I'm glad to hear some nuance introduced. That's what I was talking about in my post to the previous segment: "I think 1 problem is either/or thinking. Like so many other things, stopping climate disruption is a matter of degree. How much can we delay some of the effects, & how much can we limit the effects? Too often it's talked about as if we can just stop it at the point it's already reached. With that attitude, even if we could end greenhouse gas emissions immediately, when the effects of greenhouse gases didn't instantly stop, deniers would say, 'See? It didn't work!'"

Apr. 22 2014 11:23 AM
Michael L.

I teach statistics/econometrics so maybe this is just statistical nitpicking. But the idea that "we definitely know" something which the guest keeps saying is really misleading. Everything I've learned about statistics and science has told me that there are always measurement errors and uncertainties in any piece of empirical scientific research. So we don't definitely know anything. Just to be clear I'm not denying human influenced climate change. I'm just saying that the issues are about degrees of uncertainties not what we definitely know versus what we don't. As a scientist I'm sure the guest knows this. But I worry that some in the audience might not be as aware of the role of errors and uncertainties in science and may misinterpret what is being said.

Apr. 22 2014 11:21 AM
Nick from UWS

I can't listen to this segment. This person thinks and talks like a 14-year-old.

Apr. 22 2014 11:21 AM
Amy from Manhattan

What progress has there been in energy storage that could be used in conjunction w/solar power--often cited as a limitation for its use? What about something like supercapacitors?

Apr. 22 2014 11:20 AM

Re: Keystone pipeline. It isn't just the amount of carbon that "goes through" the pipeline - it's the amount of carbon released in the process of "mining" the tar sands (not to mrnetion the huge evvironmental destruction involved). And Canada will have even greater problems sending it through other routes. Just one example - a pipeline to the west coats would run through Native People's lands and there are treaties that could make that difficult or impossible.

Apr. 22 2014 11:20 AM
David Goessling from High Bridge, NJ

re: the "meat question"
The correct measurement of methane is a big problem that's coming into finer focus of late. See:


Apr. 22 2014 11:20 AM
Hal from NYC

So is she a lawyer too?

Apr. 22 2014 11:15 AM
fuva from harlemworld

Yes, this segment largely explains the mass apathy and inactivity over pressing issues we face: The experts, presumably with the info, cannot communicate with the people...The answer to the man's question about the interaction of normal climate change and emissions should have at least begun with ACCELERATION. But no...

Apr. 22 2014 11:14 AM

I believe there is global warming caused by humans. But I wish your guest actually answered the questions (with specifics or examples) instead of giving generic answers that sound like it came from the PR section of some generic global warming website! That's why several similar questions have been asked because the original question was never answered properly!

Apr. 22 2014 11:14 AM
Nick from UWS

This woman is completely on another planet. Brian asks perfectly simple understandable questions, and her answers have NOTHING to do with the question. Now she's talking about food security; because she heard the word "food" in Brian's question. Never mind that he didn't ask a question about food security. How can this woman possibly be any kind of scientist?

Apr. 22 2014 11:13 AM
JD from Downtown

Oligarchs, like honey badgers, don't care. They own the factories that poison the environment. They own the US government and the governments of all developing countries with any resources they an exploit. They own the errand boys and girls at the United Nations and use them to create spin and propaganda to obfuscate their dirty dirty deeds. They own the media bloviators who blah blah blah as the world burns. Anthrogenic climate change has not been proven. "Climatologists" are sketchy scientists -- they merely recite with meaningless dramatic emphasis a story they cannot verify. Junk science in the service of the usual suspects.

Apr. 22 2014 11:10 AM
Amy from Manhattan

Both of the 1st 2 q's. show why we should call it global climate *disruption* rather than warming, which sounds as if no place will get colder & sets climate science up for people who say the cold winter we just had disproved "global warming."

Climate =/= weather
Global =/= uniform

Apr. 22 2014 11:08 AM

So many words to say so much vague things.

Apr. 22 2014 11:05 AM

This woman is obviously very smart, but she is terrible at answering questions. Try again - why does global warming sometimes produce much colder weather? She ran around examples of everything else, but did not come close to addressing the caller's question.

Apr. 22 2014 11:04 AM
Nick from UWS

Is Brian not speaking English? He clearly asked how climate change is able to express as extreme cold and extreme heat simultaneously, I heard it myself. What in God's name did her answer have to do with that question? Does anybody know how to listen and then answer a specific question anymore, or is everybody's head too far up their own behinds?

Apr. 22 2014 11:04 AM
jgarbuz from Queens

What's with this annoying recent convention of starting every sentence with "So." It's particularly annoying when an alleged scientist with a British accent starts every sentence with "So.." It reminds me of back in the '60s when we started every sentence with "Like." As in, "Like, so what's up man?"

"So, when we think about blah blah blah..."

Apr. 22 2014 11:01 AM
John A

How can someone compare the emissions of a long trip by car versus the same trip by jetliner?

Apr. 22 2014 10:52 AM
Dror Kahn from Brooklyn NY

Here is a video of Isaac Asimov speaking on this topic (climate change, deforestation) in 1989. So very little has changed. He suggests how humanity may go forward.


Apr. 22 2014 10:44 AM
Marcy from Central Park

Are climate control programs (chem trails, light reflecting materials being sprayed in the atmosphere, etc.)real? Who's behind it and who's paying for it?

Apr. 22 2014 10:23 AM
Mike from Jersey City from New Jersey

Could your guest please explain the mechanisms that caused climate change in pre-industrial times?

The absence of an explanation for what causes this kind of climate change makes it harder for me to take most man-made climate change prescriptions more seriously.

Apr. 22 2014 10:21 AM

Doesn't any amount of CO2 and other GHG increase in the atmosphere both slow the escape of heat by radiation, and increase the temperature gradient for convection, everywhere in the atmosphere. It's not just where we see unusual events is it?

I've been wondering why we don't take the "crisis" as an opportunity to teach scientific thinking... ;-) There are lots of thinks people can understand better for themselves.

Apr. 22 2014 10:08 AM
Jim from NJ

With respect to climate warming due to greenhouse gas emissions, are we past the so called "tipping point"? Is there anything we can do to change the warming trend or do we just need to adapt to the new climate?

Apr. 22 2014 10:05 AM
Alex W from Chelsea

I want to buy a property that will neither be under water due to sea rise nor drought-ridden as a result of depleted fresh water stores forty years from now. What resources exist to figure out where in the United States I might consider moving given this long term concern? do you have any areas you, yourself, have considered? thanks!

Apr. 22 2014 09:35 AM

Leave a Comment

Email addresses are required but never displayed.

Get the WNYC Morning Brief in your inbox.
We'll send you our top 5 stories every day, plus breaking news and weather.